[SOLVED] Enable IMAP/POP proxy server after installed zimbra!

Hello everyone,
I have installed a zimbra server with all its package. I haven't enabled IMAP/POP proxy server in installing progress. Now, i want to configure an additional mailbox server (include: ldap-replica, zimbra-store, mta,smnp) on the new server and enable IMAP/POP proxy server on the old server. However, when i enable IMAP/POP proxy server, restart the zimbra old server, i see that tomcat is not running. So, if i can enable IMAP/POP proxy server after i had installed zimbra server? How can i configure to add an additional new mailbox server and permit IMAP/POP proxy server feature to load balancing between mailbox servers. I have read documents for this but it only says about enabling IMAP/POP proxy in installing progress.